This invention is directed to the attainment of enhanced uniformity in surface texturing and enhanced magnetic properties for thin film magnetic media.
These significant objectives are obtained through the unique utilization of substantially peritectic alloys, with these peritectic alloys being employed as a seed layer deposited as dispersed globules of a substantially homogenous and peritectic nature.
Heretofore, it has been recognized that, seed layers deposited by sputter deposition beneath magnetic media layers, may be deposited in form of islands or dispersed loci. Such is contemplated, for example, in United States Baseman et al U.S. Pat. No. 5,134,038, issued to International Business Machines Corporation on Jul. 28, 1992.
This patent proposes the utilization of a variety of island, or dispersed loci, forming seed layer materials including gallium, indium, tin, bismuth, lead, cadmium, mercury, selenium, tellerium and alloys of such metals with other metals including silver, palladium, platinum, gold, and binary and ternary compounds of the metals.
As described and presented in the Baseman et al disclosure, a seed layer of this nature comprises a "transient liquid metal" deposited underneath an intermediate metal film layer over which, in turn, a magnetic film layer is subsequently deposited. Baseman et al postulate that the intermediate film layer in this arrangement controls the reaction of the transient liquid metal comprising the seed layer and the magnetic film layer which may comprise cobalt, chromium, platinum, etc.
Other disclosures such as Yazawa U.S. Pat. No. 4,539,265 (Sony--Sep. 3, 1985) and Kawana et al European Patent Application 0 079 391 (Sony Corporation--Published May 25, 1983) disclose metals including bismuth and cobalt being operable to provide a dispersed loci or island configuration. However, it is to be noted that disclosures such as Kawana appear to contemplate that the roughness provided by the cobalt globules would be emasculated by the formation of a smooth exterior surface of the overdeposited magnetic layer.
While disclosures such as those above noted do address the possibility of forming a seed layer of an island-like or dispersed loci nature, there does not appear to be any recognition in the prior art of the unique advantages attendant upon the utilization of substantially peritectic alloys which are operable to provide an homogenous, dispersed globule type of seed layer which produces unique uniformity or homogeneity in surface texturing of the media and unique improvements in magnetics properties of the media including improved modulation and coercivity characteristics.
Moreover, these advantages are believed to be obtained without reliance upon the use of an intermediate metal film layer, which may comprise chromium, "to control a reaction between a transient seed layer and a magnetic film layer" as emphasized and disclosed in Baseman et al as being the characterizing and dominant aspect of this IBM proposal.
Having delineated what is understood to be the general state of the prior art and the basic thrust of the present invention, it is appropriate at this juncture to summarize various individually significant aspects of the invention.